First off, output sharpening is important because the method of output vastly affects the appearance of a digital image. Case in point: newsprint. I photograph regularly for a publication that is printed on traditional newsprint. The ink is applied to the paper, where it quickly soaks in and spreads out. This spreading is akin to softening, as formerly well-defined details and edges disappear into the paper along with the ink. Compare that to a print on a high-gloss substrate—one that doesn’t allow the ink to sink in, and where every little detail from the image file is reproduced in full on the page. An image file destined for either of these outputs would require dramatically different treatment to look its best. An oversharpened image will look terribly in a glossy print, whereas an under sharpened image won’t hold up on an absorbent matte paper.
That’s the “why,” but what about the “how”?
If I’m outputting a finished image file straight from Lightroom, adjusting the output sharpening is simple. In fact, it can be done directly from the Export menu. Down below Image Sizing but just above Metadata, you’ll find a few options for Output Sharpening. And they couldn’t be simpler; just match the dropdown options with the picture’s destination. The first option is the medium: are you sharpening for the Screen, for Glossy Paper, or for Matte Paper? Lightroom knows to give the latter more sharpening than the former, and just how much is appropriate—based largely on your input to the second dropdown menu. Here you select whether you’d like to apply Standard, Low or High sharpening. A resin-based matte paper, for instance, won’t require as much sharpening as true newsprint, so perhaps I’d choose less sharpening for the former destination, and more sharpening for the latter. Likewise, for on-screen images, a higher amount of sharpening is likely to be visible and look sharper than a Low level of sharpening for the screen. Once the appropriate options are dialed in, simply click Export to output the files and deliver them to their destination.
Output sharpening in Photoshop is a little trickier than in Lightroom, because you can’t simply tell the software where the image is going and count on it to sharpen appropriately. Plus, since there’s technically no “right” or “wrong” amount of sharpening, we’re talking about a purely aesthetic debate that’s impossible to win. We might know over sharpening when we see it, but what about the subtle differences between not-quite-enough sharpening and just-right sharpening? Here, it all comes down to personal preference. But, the approach to output sharpening—the straight up technique—is something subjective that can be taught. Here’s the secret: it’s the exact same technique as creative sharpening, but instead of being applied selectively, it’s applied to the entire image. Whether you want to use a high-pass sharpening technique (see last week’s tip for more on that) or the Smart Sharpen filter, the key is simply to understand a few basic tenets: output sharpening should apply across the entire image and it should simply be applied more for situations in which the output will naturally blur the image. That means a screen (no blur) requires less sharpening than a print. And a glossy print, on coated paper, (some blur) will need a bit more sharpening. And a matte print (on uncoated paper or, heaven forbid, newsprint) will require a lot of sharpening to retain its detail. Again, there’s no correct amount, but a bit of trial and error will allow you to dial in the perfect recipe for the level of sharpening that’s most pleasing to your eye.
If you’re looking for a Photoshop sharpening approach that we didn’t discuss last week (we hit Smart Sharpen and High-Pass Sharpening, two of my favorites) there’s another that’s an oldie but a goodie. It’s the Unsharp Mask filter. A lot of new photographers get confused by the term “unsharp,” but in reality, this is a tool for sharpening image files. Anyone familiar with sharpening in Lightroom’s develop module, or with Photoshop filters such as Smart Sharpen, will understand immediately how Unsharp Mask works. It’s essentially the same approach as the others—increasing midrange contrast at the edges of elements in the scene—but with fewer fine-tuning controls. Here you’ll find simply Amount (how strong should the contrast increase be), Radius (how many pixels from the edge should be impacted, and Threshold (a higher number limits the affect to stronger contrast edges, minimizing the sharpening on finer edges and details). There’s no magic number for every file size and taste, but the key is simple: look at the image file no larger than 100% view, and preferably a little wider—like 50%—in order to have a realistic view of the amount of sharpening and its impact on your images. Remember the bottom line: an oversharpened image is just as bad as one that was never sharpened to begin with. Viewing the image file at 50-100% will help you to ensure you’re doing neither too much nor too little, but in fact are getting your output sharpening just right.